<template>
    <div id="app">
      <div class="todo-container">
        <div class="todo-wrap">
          
          <!-- <MyHeader :addTodo="addTodo"></MyHeader> -->
          <MyHeader @addTodo="addTodo"></MyHeader>
  
          <MyList :todos="todos" ></MyList>
          
          <MyFooter :todos="todos" :checkAllTodo="checkAllTodo" :clearAllTodo="clearAllTodo"/>
        </div>
      </div>
    </div>
  </template> 
  
  <script>
  import pubsub from 'pubsub-js'
  import MyList from './components/MyList.vue'
  import MyFooter from './components/MyFooter.vue'
  import MyHeader from './components/MyHeader.vue'
  export default {
    components: { MyHeader, MyList, MyFooter },
    name: 'App',
    data(){
      return {
        todos:JSON.parse(localStorage.getItem('todos')) || []
      }
    },
    methods:{
      // 添加一个todo 
      addTodo(todoObj){
        this.todos.unshift(todoObj)
      },
      // 勾选或取消勾选一个todo
      checkTodo(id){
        this.todos.forEach((todo)=>{
          if(todo.id===id)todo.done=!todo.done
        })
      },
      // 删除一个todo
      deleteTodo(_,id){
        this.todos=this.todos.filter((todo)=>{
          return todo.id!==id
        })
      },
      // 全选或取消全选
      checkAllTodo(done){
        this.todos.forEach((todo)=>{
          todo.done=done
        })
      },
      // 清除已经完成的todo
      clearAllTodo(){
        this.todos=this.todos.filter((todo)=>{
          return !todo.done
        })
      },
      //更新一个todo
      updataTodo(id,title){
        this.todos.forEach((todo)=>{
          if(todo.id===id)todo.title=title
        })
      }
    },
    watch:{
      todos:{
        deep:true,
        handler(value){
          localStorage.setItem('todos',JSON.stringify(value))
        }
      }
    },
    mounted(){
      this.$bus.$on('checkTodo',this.checkTodo)
      this.$bus.$on('updataTodo',this.updataTodo)
      this.pubId=pubsub.subscribe('deleteTodo',this.deleteTodo)
    },
    beforeDestroy(){
      this.$bus.$off('checkTodo')
      this.$bus.$off('updataTodo')
      pubsub.unsubscribe(pubId)
    }
  }
  </script>
  
  <style>
  /*base*/
  body {
    background: #fff;
  }
  .btn {
    display: inline-block;
    padding: 4px 12px;
    margin-bottom: 0;
    font-size: 14px;
    line-height: 20px;
    text-align: center;
    vertical-align: middle;
    cursor: pointer;
    box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.2), 0 1px 2px rgba(0, 0, 0, 0.05);
    border-radius: 4px;
  }
  .btn-danger {
    color: #fff;
    background-color: #da4f49;
    border: 1px solid #bd362f;
  }
  .btn-edit {
    color: #fff;
    background-color: lightgreen;
    border: 1px solid green;
    margin-right: 5px;
  }
  .btn-danger:hover {
    color: #fff;
    background-color: #bd362f;
  }
  .btn-edit:hover {
    color: #fff;
    background-color: green;
  }
  .btn:focus {
    outline: none;
  }
  .todo-container {
    width: 600px;
    margin: 0 auto;
  }
  .todo-container .todo-wrap {
    padding: 10px;
    border: 1px solid #ddd;
    border-radius: 5px;
  }
  </style>